Re: [Ospf-manet] URL for MPR-extension software

Emmanuel Baccelli wrote:

> Hi Acee,
> here is a link to the source code http://ndquan.free.fr/gtnets.tar.bz2
> I must have missed Tom's post in the usual after-IETF email avalanche, 
> sorry about that ;)
> Emmanuel

Emmanuel,

I looked at your code.  It looks like all you did was modify Cisco's
Overlapping Relay (OR) code to generate LSAs that include only MPRs
and MPR selectors.

So, your GTNetS implementation is essentially just a modification
or extension of Cisco's OR solution.  In particular, you have not
implemented adjacency reduction based on MPRs, which is needed
in order to compare your solution to the MDR and OR/SP
solutions with adjacency reduction.
As Boeing has shown, both adjacency reduction and LSA reduction
are needed to achieve scalability to 100 or more nodes.
Recall the 100-node example that would have 2384 adjacencies
without adjacency reduction:
http://www3.ietf.org/proceedings/05mar/slides/ospf-5/sld17.htm

When do you plan to release code that implements adjacency
reduction based on MPRs, as described in your draft?

Since your GTNetS implementation is simply an extension of
Cisco's OR implementation, this makes me think that a separate
draft is not needed, i.e., that Cisco's OR draft and INRIA's
draft can be combined into a single draft.
Can you give any reason why this is not possible?

In any case, INRIA still needs to provide GTNetS code that
implements their solution (including adjacency reduction)
so that it can be compared to the other proposals.
Without such a comparison, it is possible (and I think likely)
that INRIA's solution will generate more than 10 times as
much overhead as MDR in a dense 100-node network, possibly
consuming all the network bandwidth.
The burden of proof is on INRIA.  Unless they can provide
evidence that their solution can support networks that are
roughly as large as those supportable by MDR, then I don't
think there is justification for accepting their draft as an
experimental WG document.

I think we should set a deadline to share current GTNetS code
before the next IETF meeting.  I plan to release updated GTnetS
for MDR in mid February.  This will be able to support more
than 100 nodes, using min-cost LSAs.  I hope that INRIA will also
release code that includes adjacency reduction.

Richard

P.S. Regarding terminology.  The term "topology reduction",
similar to "topology control", means that the actual network
topology is limited, i.e., the set of bidirectional neighbors,
or perhaps the set of adjacent neighbors.
But if you are only reducing the set of neighbors that are
advertised in LSAs, you are not reducing the topology, but
are reducing the *advertised* topology.  Therefore, I prefer to
call this LSA reduction.  Put another way, "topology reduction"
is ambiguous because it can refer to the topology defined by
bidirectional links, or by adjacencies, or by advertised links.

>

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